A composite material in which a plurality of materials are integrated and compounded can be expected to have characteristics that are not obtainable from a simple material. For example, it is anticipated that by adding a nanocarbon such as carbon nanotubes, for example, to various materials to make composite materials, the mechanical performance of a matrix can be enhanced, and electrical conduction properties, heat conduction properties, and various other types of functionality can be imparted.
A technique has therefore been proposed for obtaining a ceramic-based nano-composite powder in which carbon nanotubes are dispersed in an alumina matrix, by performing a step for dispersing carbon nanotubes in a dispersion solvent and then sonicating the dispersion solution, a step for mixing a water-soluble metal salt capable of becoming a ceramic matrix material with the dispersion solution, a step for sonicating the liquid dispersion mixture, and a step for drying/firing the liquid dispersion mixture (see Patent Document 1).
A method has also been proposed for manufacturing a solid alumina composite by obtaining an alumina composite precursor in which a nanocarbon is uniformly dispersed by dispersing the nanocarbon in a liquid aluminum compound, and then thermally decomposing the alumina composite precursor (see Patent Document 2).